Giro helmet sizes are WAANNNKKKK. I have a havoc, medium which is too small, soo i thought I would measure my head and it came in at 61, so i ordered a large 59-63, so im smack in the middle, and f**k me its huge, the strap thing goes tight to my head, but i can fit a finger in at each side. Not happy as i have too send it back and they will charge handling fees and al that bollocks. EDIT: why the hell has my litte brother left him self signed in on my computer, dickhead.